1. Field Of The Invention
The present invention relates to insect repellent compositions. More particularly, the present invention relates to substantially anhydrous insect repellent compositions that are also water resistant/waterproof, as well as sweat resistant sweatproof. The composition may also provide ultraviolet (UV) sunscreen protection from both UVA and UVB radiation. As used herein, the term “insect” is intended to mean any insect or arachnid.
2. Description of the Prior Art
Humans have long sought protection against insects. Probing and blood engorgement from insects can be annoying, painful, and sometimes may result in allergic reactions. More importantly, insects may act as vectors of diseases, such as West Nile virus and Malaria, which can be transmitted to humans. Thus, it is particularly important to repel insects from humans to prevent annoying or painful insect bites, allergic reactions, as well as it may reduce the risk of disease.
Outdoor daytime activities that expose consumers to annoying insects also expose consumers to the damaging effects of UV exposure from the sun. Scientific literature has provided an abundance of documentation regarding the harm caused by extended, unprotected exposure to UV radiation. Consumers are also aware of the potential damage that results from extended, unprotected exposure to UV radiation. Thus, consumers prefer skin products that offer UV protection.
Consumers who expose themselves to both insects and UV radiation during outdoor activity often perspire or are, in some manner, exposed to water. As a result, it is important to provide an insect repellent composition that provides uniform coverage over the peaks and valleys of the skin surface, is water resistant and/or waterproof, sweat resistant and/or sweatproof, and rub resistant and/or proof, and has sunscreen activity.
Compositions with insect repellent properties have been developed to provide protection against insect bites. Some such compositions also have a sunscreen. These compositions are typically applied to the skin before an anticipated exposure.
In water-containing emulsions and similar aqueous product forms, the insect repellent active does not become effectively available on the skin until such time as the water in the composition evaporates off and the composition dries on the skin. The start of the availability time typically takes fifteen minutes or more.
Anhydrous insect repellent compositions containing oil of citronella as the insect repellant are known. For example, U.S. Pat. Nos. 5,227,406 and 5,346,922 to Beldock et al. provide insect repellents that contain terpineol, citronella (oil of citronella), rhodinol extra, and/or geraniol. Both of these patents provide that a sunscreen may be incorporated into the insect repellent compositions. U.S. Pat. No. 5,648,398 provides that a fragrance may be added to the insect repellent compositions disclosed in U.S. Pat. Nos. 5,227,406 and 5,346,922.
U.S. Pat. No. 5,621,013, also to Beldock et al., provides insect repellents that contain citronella (oil of citronella), geraniol, crystalline 3,8 P-menthanediol, and terpineol and/or rhodinol (extra).
U.S. Pat. Nos. 5,130,136 and 5,698,209 to Sumitomo provide the use of p-menthanediol as an insect repellent.
There are also products on the market that include ethyl 3-(N-butylacetylamino) propionate. However, such ethyl 3-(N-butylacetylamino) propionate products are typically emulsions and have large amounts of water. For example, one such product, Soltan Maximum UVA Protection SPF25 lotion, has been tested and found to have water in an amount 58.3 percentage by weight (wt %) of the composition. The second such product, Nivea Sonne Anti-Mucken F4 lotion, has been tested and found to have 74 wt % water.
International Publication WO 98/19537 to Kurz et al. provides a stable, aqueous insect repellent formulation containing ethyl 3-(N-butylacetylamino) propionate stabilized with a buffer at high pH and high water concentrations.
International Publication WO 98/19538, also to Kurz et al., provides a stable, aqueous insect repellent formulation containing ethyl 3-(N-butylacetylamino) propionate stabilized with ethanol.
The references cited above that are directed to compositions having ethyl 3-(N-butylacetylamino) propionate require relatively large amounts of water. However, ethyl 3-(N-butylacetylamino) propionate in the presence of water may cause the ester group to hydrolyze to the corresponding carboxylic acid. Therefore, it is highly desirable to provide a stable substantially anhydrous insect repellent composition having one or more of the following insect repellents: ethyl 3-(N-butylacetylamino) propionate, p-menthane-3,8-diol, hydroxyethyl isobutyl piperidine carboxylate (1-piperidine carboxylic acid), or combinations thereof. None of the art cited above discloses such a topical composition, let alone such a composition that also has ultraviolet (UV) sunscreen protection from both UVA and UVB radiation, is water resistant and/or waterproof, is sweat resistant and/or sweatproof, and is resistant to rubbing and/or rub proof.